From his words and his subsequent actions, it was obvious that Xia Wuchen was very confident in his identity. He even thought that as long as he said his name, whether it was against the sect rules or not, it would go from impossible to feasible!
In fact, it was indeed the case.
It was because Xia Wuchen was a clansman of Lord Cultivator Xia Yi from the Shenhua Sect.
If one had to discuss Xia Yi and Xia Wuchen being of the same family, Lord Cultivator Xia Yi would have to address Xia Wuchen as his "brother cousin!"
With this identity, Xia Wuchen could be said to have absolute privileges in the Shenhua Sect.
Even the other lord cultivators of the Shenhua Sect could give Xia Wuchen some privileges on certain matters for Xia Yi's sake.
It allowed Xia Wuchen to gain enough prestige in the Shenhua Sect.